September LBSIG Meeting

Karmic Changes

Grub2

• The original Grub has been replaced with Grub2 in Ubuntu 9.10. (It's actually called v1.97 at the moment.)
• There are significant changes to file layout and many more features.
• At the moment (Alpha 5), Karmic installation does not automatically add Grub menu entries for other bootable partitions. When you re-boot after installation, it looks as if Karmic is the only thing on the computer. Relax — they're there, but you have to manually add them to the menu.
• Unlike Grub-1, you cannot change the boot menu by simply editing /boot/grub/menu.lst. To get the "dual-boot" entries, from a 9.10 command prompt issue the following: sudo update-grub
• This will generate a new /boot/grub/grub.cfg file with entries for all bootable images (Windows or Linux) found. Note that the "extra" entries will be in ascending order, so the one you probably want (other than the Karmic entry, which will be first) will be the last one in the boot list.
• If you are maintaining two versions (Jaunty and Karmic, e.g.), then if you update Jaunty to have a new version of the kernel, you'll have to boot into Karmic and re-run update-grub to have it appear (last) in the boot list.

Kubuntu Changes

• KDE 4.3.1
• The people in charge have given up on their bright idea of replacing Konqueror with Arora. The latter will be available, but Konqueror will be the default.
• OpenOffice now has "KDE Integration" — that is, OO will have the same "Oxygen" look and feel as the other KDE apps.
• A Gnome system settings application, so you can change fonts, widget style, etc. for Gnome apps running under KDE.

Ubuntu Changes

None worth mentioning.

Image Formats

Raster

Raster formats store a color value for each pixel. These can be 1-bit (black and white), 8-bit (256 total colors), 16-bit (64K), 24-bit (16M), or 48-bit (256T). These can be lossless or lossy, depending on the compression algorithm used.

• JPEG — 24-bit, lossy compression, small, good for distributing photographs. Loses more quality every time it is edited, so should not be used for images which will be modified. Web-OK.
• GIF — 256 mapped colors, very small, lossless compression, good for icons. Can't handle continuous tones. Has transparency. Web-OK.
• PNG — 24-bit, lossless compression, big, excellent for photographs. Has transparency. Web-OK.
• TIFF — Very flexible with many variations. Everything from 1-bit (black and white) to 48-bit, lossless compression, huge. Has transparency. Preferred by commercial printers and OCR software. Can have more than one page per file.
• BMP — Microsoft-only, large. Web-OK.
• RAW — Not a "real" format; each camera has a different one. Often has more color depth than JPG.

My basic recommendation is to store original images (scans, photographs) as PNG or possibly TIFF. Since your camera won't do that, immediately convert the JPG to PNG for storage and editing. Do all your editing and retouching on the retained full-resolution PNG file, and then make a JPG file as a "final" copy if you need something smaller. This can be generalized: No matter what editing programs you use, never create a JPG unless you know it will never be modified.

Vector

Vector files are kept as mathematical formulas, not as dot images. Vector images cannot be displayed; pixels are generated only when ready to display or print. As such, they are infinitely scalable until they are converted to raster. Most vector formats are proprietary (e.g., Corel Draw), but by far the most common are the .TTF (Truetype) or PFx (Postscript) scalable fonts.

• SVG — Large, very compressible (really an ASCII XML file). Open-source. Web-OK.
• CGM — an ANSI standard but now obsolete.
• DXF — Autocad native format.

Mixed

Document Publishing

• Postscript — vector format which can have embedded raster sections, called EPS (encapsulated PS).
• PDF — can contain vector and raster (usually JPG) sections.
• DjVu — free alternative to PDF. Much smaller files while remaining readable. Often used to distribute documents which contain illustrations over the net.

Editing

• Photoshop (.psd), Paint Shop Pro (.psp), and Gimp (.xcf) — proprietary formats allowing multiple layers, where some are raster and some are vector. (These are all raster editors which use vector layers for lettering.)
• Corel Draw (.cdr) — a vector editor which can embed raster sections.

Inkscape

• Open-source vector graphics editor.
• Native format is SVG. It can input from Corel Draw, etc. and it exports to PNG, XCF (Gimp), and more.
• See http://tavmjong.free.fr/INKSCAPE/MANUAL/html/ for a free book with lots of step-by-step examples.
• Workflow:
  1. Use Inkscape to create your graphic.
  2. Save it in SVG format.
  3. Determine how large a raster image you need, and save it in PNG.
  4. If you need a different-sized image, go back to the original SVG and re-save in PNG.